[unreadable] We propose a Stage 1 study to adapt and test an efficacious group CBT treatment for depression for use with clients in AOD treatment who report persistent depressive symptoms. The goal of the revised therapy is to reduce depressive symptoms and improve AOD outcomes. The original protocol, a 16-session group CBT therapy for depression, has demonstrated efficacy in multiple RCTs. Although this protocol seems particularly suited to public AOD treatment settings, it does not address many issues relevant to the treatment of depression in clients with AOD disorders. Our study seeks to move the CBT and AOD fields forward by narrowing the gap between research and practice. First, by adapting the therapy to the population and setting, we hope to improve its efficacy. Second, we involve key stakeholders in the entire research process. This will ensure that the treatment developed will be feasible, as well as acceptable to patients and providers, while maintaining the theoretical foundations of the existing therapy, increasing the likelihood the intervention will be adopted and sustained. We build upon an existing relationship between RAND and BHS, the largest publicly funded AOD treatment provider in Los Angeles County. Our specific aims are (1) To adapt an existing group therapy (CBT for depression), creating a manualized treatment for use with clients with persistent depressive symptoms and AOD disorders, along with accompanying implementation measures and tools, and to obtain preliminary assessments of the treatment from patient and provider perspectives and (2) To conduct a pilot test of the revised treatment in which we (a) demonstrate that when the therapy is implemented with fidelity, clinically significant reductions in depressive symptoms and AOD use occur; (b) estimate the likely effect size; and (c) investigate the underlying mechanisms of change, including both cognitive-behavioral and group processes and their relationship to depression and AOD treatment outcomes. Using a randomized design, we will enroll 84 clients with persistent depressive symptoms in one of two conditions: (1) usual care (UC) and (2) UC plus 16 sessions of group CBT for depression. Subjects will complete: (1) a baseline interview, (2) a post-treatment interview (at the conclusion of the CBT treatment) and (3) a follow-up interview (3 months after CBT treatment ends). At the end of this pilot, we will have a manualized intervention, sufficient data to estimate the intervention effect size, and a well-described process for involving providers and clients. [unreadable] [unreadable] [unreadable]